Carbon dioxide diffuses across the alveolar-capillary membrane approximately how many times faster than O2?
a. 10
b. 20
c. 30
d. 40
Q. 2 Which of the following gases would diffuse fastest across the alveolar-capillary membrane?
a. Air
b. Carbon dioxide
c. O2
d. Nitrogen
Q. 3 Assuming a constant FiO2 and carbon dioxide production, which of the following statements is correct?
a. An increased PACO2 will result in and increased PAO2.
b. Increased FIO2 blows off carbon dioxide.
c. Increases in alveolar ventilation (VA) decrease the PACO2 and increase the PAO2.
d. The PAO2 varies proportionally with the PACO2.
Q. 4 What is the highest PAO2 one could expect to observe in an individual breathing room air at sea level?
a. 90 to 100 mm Hg
b. 110 to 120 mm Hg
c. 640 to 670 mm Hg
d. 710 to 760 mm Hg
Q. 5 Which of the following conditions must exist for gas to move between the alveolus and pulmo-nary capillary?
a. Adequate alveolar ventilation (VA)
b. Difference in partial pressures (pressure gradient)
c. Normal central nervous system (CNS) control mechanism
d. Sufficient amount of blood hemoglobin (Hb)
Q. 6 Which of the following layers must be traversed by gases moving across the alveolar-capillary membrane?
1. Alveolar epithelial membrane
2. Capillary endothelial membrane
3. Interstitial space
4. Transbronchial radial tethering mechanisms
a. 1, 2, and 3 only
b. 1, 2, and 4 only
c. 2 and 3 only
d. 1, 2, 3, and 4
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